Electrical knife sharpening device

ABSTRACT

A knife sharpening device includes a base with a motor and a gear reduction assembly connected thereto. A main shaft is connected to the gear reduction assembly and two grinding disks are mounted on the main shaft. A separation tube is mounted on the main shaft and located between the two grinding disks. Each grinding disk has a spring urging thereto so as to prevent the grinding disks from shaking. A cover is mounted to the base and has straight slots each of which is in communication between two openings. Each slot includes two narrow ends which communicate with the two openings so that the blades of knives are inserted perpendicularly in the slots and the cutting edge is slightly clamped by the narrow ends.

FIELD OF THE INVENTION

[0001] This is a Continuation-In-Part application for applicant's formerapplication with the application Ser. No. 09/905,805 having the sametitle as the application.

BACKGROUND OF THE INVENTION

[0002] A conventional electrical knife sharpening device generallyincludes a motor which drives one or two grinding disks directly so thatthe rotational speed of the grinding disks is so high that could damagethe edges of blades of the knives. Besides, once the grinding disks arenot installed at their proper positions, the high rotational speed ofthe grinding disks will make the grinding disks tremble and generatenoise.

[0003] U.S. Pat. No. 6,012,971 discloses a sharpening apparatus that hastwo pairs of inclined slots for being received the blades which aresharpened by the abrasive material. However, the blades have to beinserted into the slots at an angle relative to the top of the casing ofthe apparatus and this is not convenient for the users to operate. Inother words, the users have to carefully insert the blades in thegrooves otherwise the cutting edges may be hit by the casing of theapparatus. U.S. Pat. No. 5,245,789 discloses another knife sharpenerwhich has a slot that allows the knife to be perpendicularly inserted.Nevertheless, the slot includes two dead ends which could touch anddamage the cutting edge of the knife to be sharpened.

SUMMARY OF THE INVENTION

[0004] In accordance with one aspect of the present invention, there isprovided an electrical knife sharpening device which comprises a baseand a motor is connected to the base. A gear reduction assembly isconnected to an output shaft of the motor and a main shaft respectively.Two grinding disks are mounted to the main shaft and a separation tubeis mounted to the main shaft and located between the two grinding disks.Two springs are mounted on the main shaft and push the two grindingdisks toward the separation tube. A cover is mounted to the base and hasslots defined therethrough to access the grinding disks. Each slotallows the blade

[0005] The primary object of the present invention is to provide a knifesharpening device wherein each slot is a straight slot and includes twonarrow ends which are in communication to two respective openings suchthat the cutting edge of the blade is slightly clamped by the narrowends and not be damaged.

[0006] Another object of the present invention is to provide a knifesharpening device that has a gear reduction assembly connected to themotor and the grinding disks are pushed by two springs so as to bemaintained in a correct position.

[0007] The present invention will become more obvious from the followingdescription when taken in connection with the accompanying drawingswhich show, for purposes of illustration only, a preferred embodiment inaccordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is an exploded view to show a knife sharpening device ofthe present invention;

[0009]FIG. 2 is a perspective view to show the knife sharpening deviceof the present invention;

[0010]FIG. 3 is a top view of the knife sharpening device of the presentinvention;

[0011]FIG. 4 is a side view to show the knife sharpening device of thepresent invention;

[0012]FIG. 5 shows the other side of the knife sharpening device of thepresent invention;

[0013]FIG. 6 shows the slots are straight in the mask;

[0014]FIG. 7 is a cross sectional view to show the knife sharpeningdevice of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0015] Referring to FIGS. 1 to 3, the knife sharpening device of thepresent invention comprises a base 10 having a plurality of separationplates and a plurality of recesses 11, 12, 13 and 14 are defined inthese separation plates so that a motor 20, a gear reduction assembly 30and two grinding disks 54 are installed in the recesses 11, 12, 13 and14. A cover 60 is mounted to the top of the base 10 by extending bolts61 through tubes 15 in the base 10 and engaged with the cover 60. Anopening is defined in a top of the cover 60 and has two positions 62 forreceiving the grinding disks 54. A mask 70 is connected to the openingof the cover 60 by screws 71 and a plurality of slots 72 are definedthrough the mask 70 and each slot 72 is a straight slot 72 as shown inFIG. 6. Further referring to FIGS. 4 and 5, each slot 72 is incommunication between a circular opening 721 and a rectangular opening722. The two openings 721, 722 communicate with the slot 72 such thatwhen the blade 81 of a knife 80 is inserted in the slot 72, the cuttingedge is slightly clamped by the two narrow ends of the slot 72 and willnot be hit by the mask 70 because the two openings 721, 722 receive thecutting edge even if the cutting edge penetrates through the two narrowends.

[0016] The motor 20 has an output shaft 21 to which a ventilation fan 22and a gear reduction assembly 30 are respectively connected to two endsof the output shaft 21. A main shaft 40 is connected to a central rod 31for connecting the gears of the gear reduction assembly 30. Two grindingdisks 54 are mounted to the main shaft 40 and a separation tube 55 ismounted to the main shaft 40 and located between the two grinding disks54. Two springs 53 are mounted on the main shaft 40 and push the twogrinding disks 54 toward the separation tube 55. Two grooves 41 aredefined in the main shaft 40 and two retaining washers 51 are mounted tothe main shaft 40 and contact an end of each of the springs 53. TwoC-shaped clips 52 are engaged with the two grooves 41 to keep theretaining washers 51 in position. A cap 56 is mounted to an end of themain shaft 40.

[0017] Referring to FIG. 7, the grinding disks 54 are pushed by thesprings 53 so that the grinding disks 54 can be maintained toward theseparation tube 55. The speed of the grinding disks 54 is properlycontrolled because of the gear reduction assembly 30. A grinding surfaceof each of the grinding disks 54 is located at angle relative to theslot 72 so that when the blade 81 is inserted in the slot 72 inperpendicular to a horizontal plane, the grinding surface of thegrinding disk 54 sharpens the blade 81 at a correct angle.

[0018] Because the slots 72 are straight, the users need not to tilt theblade 81 before being inserted into the slot 72 and the users justinsert the blade 81 perpendicularly into the slot 72. This is convenientfor the users. Besides, the cutting edge of the blade 81 will notcontact the mask 70 so that the cutting edge is not damaged duringoperation.

[0019] While we have shown and described the embodiment in accordancewith the present invention, it should be clear to those skilled in theart that further embodiments may be made without departing from thescope of the present invention.

What is claimed is:
 1. An electrical knife sharpening device comprising: a base; a motor connected to the base and a gear reduction assembly connected to an output shaft of the motor, a main shaft connected to the gear reduction assembly, two grinding disks mounted to the main shaft and a separation tube mounted to the main shaft and located between the two grinding disks, two springs mounted on the main shaft and pushing the two grinding disks toward the separation tube, and a cover mounted to the base and having straight slots defined therethrough to access the grinding disks, a grinding surface of each of the grinding disks being located at an angle relative to the slot corresponding thereto.
 2. The knife sharpening device as claimed in claim 1 wherein each straight slot is in communication between two openings.
 3. The knife sharpening device as claimed in claim 2 wherein each straight slot includes two narrow ends which communicate with the two openings respectively. 